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Red versus Infrared: Comparing 900nm and 1550nm Lidar performance in arctic winter conditions
No full textWe present here the results of a data collection campaign involving a 1550nm and 900nm lidar operating in severe winter weather conditions. Data for both lidars was collected simultaneously during arctic-like conditions where fine snow or ice particles are often suspended in the air severely reducing visibility. In this work we qualitatively and quantitatively compare the performance of these lidars. Performance is compared with respect to clutter noise from scattering, object detection in the presence of snow. We find the 1550 nm lidar is more likely to detect snow, resulting in increased clutter noise
IoT-Enabled Circular Supply Chains: Advancing Sustainability in the United States Logistic and Distribution
No full textA shift in logistics and distribution systems has been underway to accomplish the sustainability agenda, where the merging of circular economic principles with IoT is the key to the transformation. In this chapter, the IoT-enabled Circular Supply Chains (CSCs) concept discussion goes further as it can enhance overall operations efficacy and transparency and drive towards a carbon-zero goal in the US. It employs the thematic content analysis of literature, industry publications, and practical case studies (e.g., including Walmart, Amazon, and HP) in order to provide an overview of Digital Circular Logistics (DCL) by utilizing a qualitative descriptive approach. In order to provide a systematic method for long-term change, a theoretical framework is established to integrate Internet of Things (IoT) features like blockchain traceability, real-time monitoring, and predictive analytics with CE\u27s 9R tactics. Despite a high level of technological preparedness, the results show that growth is nevertheless hindered by systemic impediments such as limitations of policy frameworks, organizational stagnation, and a lack of cross-sectoral cooperation. This chapter provides academics, practitioners, and policymakers with theoretical understanding as well as practical advice by expanding socio-technical and institutional theories. It markets itself as a road map for wealthy nations to implement intelligent, circular logistics systems speedily
Mechanics Post-TAVR for Trileaflet vs Bicuspid Aortic Valves: Insights from Computational Simulation
No full textBackground: Bicuspid aortic valve (BAV) disease is the most common congenital heart defect and is associated with elliptical openings and excess calcification. Limited data are available on long-term efficacy of transcatheter aortic valve replacement (TAVR) for BAV patients.
Objectives: The purpose of this study was to compare simulated mechanical metrics post-TAVR between BAV and trileaflet patients with calcific aortic stenosis.
Methods: Pre-TAVR computed tomography scans of trileaflet (n = 22) and BAV (n = 25) were used to segment the aortic valve. Simulated balloon-expandable stent deployment was performed from a previously developed protocol. The bioprosthetic leaflets were then pressurized under a physiological pressure. Stent waist expansion ratio, aspect ratio (AR), leaflet systolic normalized geometric orifice area (GOA), and maximum leaflet diastolic stress were measured.
Results: BAVs had lower waist expansion ratio (87.8% ± 2.6% vs 89.4% ± 1.4%; P \u3c 0.001), lower waist AR (94.6% ± 2.8% vs 98.2% ± 1.0%; P \u3c 0.001), lower normalized GOA (88.9% ± 0.8% vs 89.5% ± 0.7%; P \u3c 0.01), and higher maximum stress (2.81 ± 0.44 vs 2.29 ± 0.25 MPa; P \u3c 0.001) on average compared to trileaflet patients, respectively. Within the BAV group, calcium volume was correlated with waist AR (r = −0.75, P \u3c 0.001), normalized GOA (r = −0.68, P \u3c 0.001), and maximum stress (r = 0.66, P \u3c 0.001).
Conclusions: Balloon-expandable TAVR for BAV has worse simulated mechanical metrics compared to TAVR for trileaflet aortic valve patients and is associated with high calcium volume
Multiscale Characterization of Dislocation Cell Structures in LPBF Processed 316L Stainless Steels
No full textThe Combinatorics of Integer Partitions Enumerated by some Exotic Weights
No full textIdentities of integer partitions generally state that two dissimilar appearing families of partitions are in fact equinumerous when both are restricted to any fixed size. Euler\u27s theorem is a classic example of such an identity, which equates the number of partitions with odd parts to the number of partitions with distinct parts. Lately, analogs of known partition identities involving weights other than size have begun to attract research interest. This dissertation is an investigation of two such weights. In Chapter 2, we study Schmidt weights, which count only parts with indices belonging to some given subset of the positive integers. This is motivated by recent work of Andrews and Keith, which produced a highly general partition identity involving Schmidt weights that allowed new q-series sum-product identities to be discovered, including an identity that is a generating function for 2-colored partitions. We further generalize their partition identity, and use a special case of this new result to derive a companion to their 2-colored identity for overpartitions. Then, in Chapter 3 we prove an infinite family of q-series identities which generalizes the 2-colored identity to t colors, for any t at least 2. Finally in Chapter 4, we study the partition perimeter, which is defined to be one less than the sum of the largest part and number of parts. A purely combinatorial proof for a perimeter analog of a classic identity of Glaisher recently found by Amdeberhan, Andrews, and Ballantine is given. We use similar methods to prove a generalization of a perimeter identity of Fu and Tang as well
SPDK+: Low Latency or High Power Efficiency? We Take Both
No full textSPDK, as one of the most efficient I/O storage software, is capable of delivering the lowest I/O latency. Unfortunately, the polling mechanism in SPDK wastes tremendous CPU clock cycles, especially under small I/O operations and low queue depths. Although SPDK supports the conventional interrupt method, it does not improve power efficiency under such circumstances. To address this issue, we propose SPDK+, which enables the user interrupt feature in the SPDK to achieve both low latency and high power efficiency. Specifically, SPDK+ employs user interrupt handling to directly process MSI-X interrupts from SSD devices and utilizes user wait instructions during IO wait periods to conserve power. The comprehensive evaluation results show that SPDK+ achieves up to 49.5% power efficiency improvement while keeping the I/O latency almost unchanged compared with SPDK
Hourly Simulated Power Production Data with Snow Loss Model at Queued Utility-Scale PV Sites Simulated as Fixed-Tilt Systems in the U.S. Eastern Interconnection for Weather Year 2020
No full textUsing 2020 weather data, we ran PySAM power production simulations for utility-scale PV sites in the U.S. Eastern Interconnection queue. Site IDs, capacities, and locations (counties) were extracted from Lawrence Berkeley National Laboratory’s Queued Up: 2024 Edition dataset. No panel mount information was provided, so all sites were assumed to be 30-degree, fixed tilt systems. Sites’ latitudes and longitudes were assumed to be the centers of the installation counties. See queued_site_metadata.csv file for individual site metadata
Hourly Simulated Power Production Data with No Snow Loss Model at Queued Utility-Scale PV Sites Simulated as Single-Axis Tracking Systems in the U.S. Eastern Interconnection for Weather Year 2020
No full textUsing 2020 weather data, we ran PySAM power production simulations for utility-scale PV sites in the U.S. Eastern Interconnection queue. Site IDs, capacities, and locations (counties) were extracted from Lawrence Berkeley National Laboratory\u27s Queued Up: 2024 Edition dataset. No panel mount information was provided, so all sites were assumed to be the centers of the installation counties. See queued_site_metadata.csv file for individual site metadat